Process of coating wire with metal.



G. L. MEAKERL I PROCESS OF COATING WIRE WITH METAL.

APPLICATION'HLED JUNE 27)!913.

Patented July 18, 191

GUY L. MEAKER, OF JOLIET, ILLINOIS.

'Paocnss or COATING WIRE WITH METAL.

I Specification of Letters Patent. Patented, July 1916.

Application filed June 27, 1913. Serial No. 776,151.

To all whom it may concern:

Be it known that I, GUY L. MEAKER, a citizen of the United States,residing at Joliet, in the county of Will and State'of Illinois, haveinvented a new and useful 'Process of. Coating Wire with Metal, of whichthe following is a specification.

My process is especially intended and adapted for-coating iron or steelwire with zinc or spelter commonly known as galvanizing, though as willappear from the following specification it is in some of its featuresapplicable to other coating. processes. In the following specification Ihave specifically described the process with reference to its employmentfor galvanizing wire but it is'to be understood that the specificdescription is for the purpose of exemplification only and that thescope of the invention is to be determined from the following claims, inwhich I have endeavored to distinguish it from the prior art so far asknown to me without, however, relinquishing or abandoning any partthereof.

Coating metal'with metal and more specifically galvanizing is ordinarilyaccomplished by either of two processes, the first electrochemical inits nature, the metal being de-' posited from a solution, and thesecond, which is the more generally employed so far as galvanizing isconcerned, the so-called hot process in which the metal to be coated issubmitted to a bath of hot coating metal. My invention relates moreparticularly to this latter process and to its applicatlon for coatingor galvanizing iron or steel wire.

The steps involved in galvanizing wire consist of annealing, cooling,cleaning or pickling, usually in hydrochloric acid, washing, fluxing andpassing the wire through the molten spelter or zinc to accomplish thecoating. Ordinarily the steps of the process occur in the order in whichthey have just been recited. So far as the ultimate result of thetreatment is concerned, the order of the annealing step of the processis unimportant so long as it precedes the galvanizing step, but it hasheretofore been performed prior to'fluxing the wire upon the theory thatthe heat of annealing v would dissipate the flux which is ordinarilyeither ferrous or zinc chlorid. Obviously, however, with the annealingstep,-the,first in the process, and the galvanizing step, the last,

and with ,the intermediate steps consisting of immersing the wire inaqueous baths for pickling, washing and fluxing, theheat used inannealing the wire is dissipated before the last step is reached Inorder to secure the best results however the wire must be hot when itenters the galvanizing bath in order to open its pores that it mayproperly receive the coating or spelter and such a close unlon be"formed between the wire or steel and the zinc that the coating will notflake or peel ofl'. It has been customary therefore after the pickling,washing and fluxing operations toreheat the wire prior to its entry intothe spelter tank. Thisreheating as well as the preceding steps followingthe cleaning of the wire under ordinary practicefurnish opportunity forreoxidation of the wire and consequent interference with perfectgalvanization.

The objects of my invention are to overcome the objections anddifliculties above pointed out and to provide aprocess in which a singleheating of the wire is suflicient for both annealing and galvanizing andno opportunity is presented for oxidization of the wire after theannealing operation.

With these objects in view my process contemplates the reversal of therelative positions of the steps of annealing and fluxing as usuallycarried out and the use of but one heating agency for the annealing andcoating operations.

In my process the green wire or wire as it comes from the drawingoperation'is cleaned to remove any oxidation products or scale formed inthe drawing operation by pickling and'washing and is then fluxed, allthese operations .as well as the drying of the wirebeing performedbefore the annealing operation. The latter immediately precedes thecoating with metal and 1s so performed with relation to that step thatno opportunity is afforded for the acquisition of oxids or scales by thewire. The wire is boiling point above the annealing temperature and isalso stable thereat.

In the accompanying drawings, I have illustrated apparatus for carryingmy proc ess into efiect but such apparatus is not a part of the presentinvention, which may be carried out in other forms of apparatus, but

forms the subject matter of another application. Serial No. 776,150filed by me omthe spelter tank. From the flue 13 the products I same dayherewith.

ill

lln'said drawing, Figure I is a diagram-' matic view of a completeapparatus for carrying out my process; Fig. 2 a "vertical longitudinalsection of that portion of the apparatus in which the steps of annealingand galvanizing are. carried out; and Fig. 3 a cross sectional detail.

Referring first to Fig. 1, it will be seen that the apparatus thereshown is adapted for the n simultaneous treatment of four strands ofwire though obviously if desired the construction could be modified forthe treatment of a greater or less number of strands. Four wire reelsare shown at A the wire from which passes over a guide B into andthrough a hood C and through a pickling bath'D of dilute hydrochloric orother suitable acid, a washing tank E which may contain water and afluxing tank F containing a suitable flux. As heretofore stated the fluxwhich I preferably employ must. be unafi'ected by the annealingtemperature of 1300" F. and with this in view I have chosen zinc chloridwhich has aboiling point of approximately 1436 F. and is stable at thattemperature as suitable for the-practice of my process though as abovestated other. fluxes capable of resisting the annealing.

temperature employed may. be substituted therefor. vThe wire coming fromthe reels is led through the baths in the order stated around aroller orstationary guide G whence it is carried back beneath the hood to bewholly or partially dried by the heat arising from heated baths E, F.From the hood C the wires are carried to a furnace H provided withsuitable heating means as with that to be presently described andcontain:

ing one or more longitudinal tubes I through which the wires are passedto be heated on their way to the galvanizing bath K. From the latter thewires are ledaway to be cooled and reeled up ready for use.

ing to Fig. 2, the furnace construction by which the annealing tubes andspelter bath are heated comprises a fire box 3 having the grate bars 4:and supplied with air through an air flue 5. The latter receives itssupply of air from an intake due 6 having a perforated cover 6' arrangedintermediate the heating chamber 7 and that portion of the furnace whichsurrounds and heats the spelter bath K. Flue 6 co cates with a'pair ofside dues 9 arranged on .opposite sides of the downcomer due 10 formentioned, thence through the 'downtake an uptake flue 13 arrangedbeneath the pass along the horizontal flue 14 beneath thespelter tankand provided with suitable bafies 15- from which they pass into thedowntake 16 and so to the chimney at 17. At 18 I have shown asupplemental fire box beneath the spelter tank and communicating withthe fiue 13 by a passage 19. Ordinarily this supplemental fire box isemployed only in starting the furnace. Above the flue l4 and forming thetop wall thereof is a spelter tank K with the interior of whichcommunicate one or more annealing tubes 1 the main bodies of which arecontained in the heating chamber 7 where they are raised to an annealingtemperature. At the entering end the tube or tubes are upwardly inclinedas at 20 to tacilitate the entrance of the wires to he annealed and atthe other end they extend across and are cooled by the flue 6. Beyondsaid due they abut against the vertical wall of the spelter tank towhich they are connected by reducing bushings 22 having flanges on theinside of said tank and extending a little way into the ends of thetubes. Each tube is preferably provided with partitions 21 see Fig. 3 sothat it. may be employed for the heating of a set of wiressimultaneously without their ,in any wise interference with each other.Within the tributes itself through the annealing tubes 20 within whichit surrounds the wires in the various compartments and rises, at theintake end of said tubes to a level intermediate the levels of the leadand spelter respectively in the coating tank. The lead within the tubesis heated to an annealing temperature and evenly heats the wires to thesame temperature.

The steps of the process have already been described but may berecapitulated as follows: The wire or wires from the reels A.

pass successively through the pickling, Washing and flum'ng tanks aroundthe roll G and again under the hood C where they are dried by thecurrents of hot air rising from and around the baths. From the hood 0the wire passesthrough the tubes 20 in which the several strands arereceived and heated to an annealing temperature. lhence the wiresemergeinto the lead bath 27 and pass upwardly into the spelter bath- 26through which they are guided in a horizontal course by the guide rods24, 25 finally emerging in an annealed and coated condition at the endof the tank. Obviously a number of tubes may be used depending upon thenumberof separate strands of Wire to be treated.

The heated gases and products of combustion from the fire box 3 firstcome in contact with the tubes I Whichare highly heated thereby, andthen pass to the tank K which they also heat but to. a lesser degree.The wires are therefore heated to an annealing temperature in the tubesI and after being cooled somewhat in that portion of the tubes whichtraverse flue 6 enter the spelter at temperature which is considerablyhigher than the temperature of the coating metal,

this being a condition which is necessary for the best results incoating with metal. The continual passing of the highly heated wiresfrom the annealing tubes into the spelter bath also assists inmaintaining the temperature of the latter. The lead of the annealingbath has no tendency to coat or alloy with.

the iron or other metal of the wires notwithstanding the presence of theflux thereon nor does it materially affect the coating of the flux whichis retained by the wires at the time they enter the spelter bath andassists in securing a firm union between the metal of the wire and thecoating metal. From the time; that the wire enters the annealing tubesuntil it, leaves the spelter bath it is at no time exposed to oxidationand but one heating is required which serves not only for the annealingbut also for the coating operation, thus saving materially in the fuelcost. By using as the flux a material stable and non-volatileatthetemperature used for annealing the latter step in no way interfereswith the fiugr. The lead employed being practically covered or inclosed,in part by spelter and in part by the annealing tubes, the danger frompoisonous fumes therefrom is negligible. Also the life of the spelterpan is increased by reason of the fact that it is in the main protectedby the lead from the direct action of the spelter especlally at thebottom where the heat is the greatest.

I claim: '1. A process of coating with metal con- 7 sisting in forming abath of non-adherent material and a bath of coating metal in contactwith each other, raising the bath of nonadherent material to anannealing temperature and passing the article to be coated suceessivelythrough the non-adherent material A process of coating Wire with metalch consists 1n forming a bath of nonatiiherent material and a bath ofcoating metal in contact with each other, raising the bath ofnon-adherent metal to an annealing temperature and passing the wiresuccessively through the non-adherent -materialand through the bath ofsp 1t 4. A process of coating'with metalconsisting in supporting a bathof coating metal upon a bath of heavier non-adherent metal, heating thelatter to an annealing temperature and passing the article to be coatedfirst through the bath of non-adherent metal and then through the bathof coating metal.

5. A'process of coating with metal consisting in maintaining a bath ofnon-adherent metal at an annealing temperature, malntaming a bath ofcoating metal at amaterially lower temperature in contact therewlth andpassing an article to be coated through the annealing bath, the surfacesof contact between the annealing and coating bath and through the latterbath.

6. A process of annealing and coating wire, consisting in maintaining abath of non-adherent metal at an annealing temperature, maintaining abath of coating metal in contact therewith at a non-annealingtemperature and passing the wire T .through the annealing bath, thesurfaces ofcontact of the baths and the coating bath.

7. The process of coating with metal consisting in maintaining a bath ofnon-adherent metal at an annealing temperature,

maintaining a bath of coating metal in con-' tact with the first saidbath at a temperature below an annealing temperature, fluxing thearticle to be coated and passing it first through the annealing bath,then through the surfaces of contact between the annealing and coatingbath and then through the latter said bath.

i 8. The process of coating with metal consisting in. maintaining a bathof non-adherent metal at an annealing temperature, maintaining a bath ofcoating metal in contact with the first said bathat'a temperature belowan annealing temperature, fluxing the' wire to be coated and passing itfirst through i the annealing bath, then through the surfaces of contactbetween the annealing and coating bath and then through the latter 1said bath.

9. '"A'process of coating wlth'metal consisting in maintaining anannealing and a coating bath in contact with each other, maitaining aportion of said anneallng bath at an annealing temperature and theremaiader of said bath at lower temperatures, maintaining the coatingbath at a temperature below that of the annealing bath and passing thearticleto be coated first through the annealing bath, then through thesurfaces of contact between the annealing and the coating baths and thenthrough the lat ter said bath.

10. A process of coating with metal consisting in maintaining anannealing and a coating bath in contact with each other, maintaining 'aportion of said annealing bath at an annealing temperature and theremainder of said bath at lower temperatures, maintaining the coatingbath at a temperature below that of the annealing bath and passing thewire to be coated first through the annealing bath, then through thesurfaces of contact. between the annealing and the coating v baths andthen through the lattersaid bath.

11. A process for coating wire with metal consisting in maintaining anannealing bath and a coating bath in contact with each other, heatingthe portion of the annealing bath more remote from the coating bath toan annealing temperature, reducing the Witnesses manage temperature ofthe annealing bath adjacent the coating bath, maintaining the coatlng ata lower temperature than the annealing bath and passing the wiresuccessively.

an annealing temperature and another portion at amaterially lowertemperature, sup porting a bath of .coating metal upon the coolerportion of the annealing bath, heating the coating bath in contact withthe cooler v portion of the annealing bath and passing the Wiresuccessively through the annealing bath, the-surfaces of contact of theannealing bath and the coating bath, and through the coating bath. 1,

- A GUY L. MEAKER.

Envm T. Gms'r, JOHN H. GARNSEY.

